Fix 'Unknown parameter 'storage'' issue
    
    Change-Id: Icba6e0defe87095d76dec723cda10ff1e13fdeb4
    Signed-off-by: Junqin Zhou <juzhou@redhat.com>
    Reviewed-on: https://code.engineering.redhat.com/gerrit/178204
    Tested-by: Libvirt Jenkins <libvirt-jenkins@redhat.com>
    Reviewed-by: Liping Cheng <lcheng@redhat.com>
    Signed-off-by: Liping Cheng <lcheng@redhat.com>